Abstract

Microlens fabricated on fiber endfaces in the form of a hemispherical core¹ or a chemically etched conical core² offer good coupling efficiency and reduced alignment complexities in single-mode fiber- to-laser coupling. In this paper, we report a conical microlens which, unlike the chemically etched conical core, is fabricated by polishing the entire fiber endface in a conical shape. Compared with tapered hemispherical lenses, polished conical lenses have similar coupling efficiencies but significantly lower reflectance. Thus, in some applications, the use of a polished conical microlens may have the potential of eliminating an optical isolator in laser modules.

© 1992 Optical Society of America